A liquid electrolyte (i.e., an electrolytic solution) has been used in electrochemical devices such as cells, capacitors, sensors, displays and recording devices. However, a liquid electrolyte lacks reliability in long-term use or storage because of a fear of a leak.
Nature, vol. 353, pp. 737-740 (1991) and U.S. Pat. No. 4,927,721 disclose a photoelectric conversion device comprising a dye-sensitized particulate semiconductor and a photo-electrochemical cell having the device. In this technique, too, a liquid electrolyte is used as a positive hole transporting layer, and there is a fear that the device will be short of the electrolytic solution due to evaporation in long-term use only to have a seriously deteriorated photoelectric conversion efficiency or fail to function as a device.
In order to overcome this disadvantage, WO93/20565 proposes a photoelectric conversion device comprising a solid electrolyte, and JP-A-7-288142 (the term “JP-A” as used herein means an “unexamined published Japanese patent application”), Solid State Ionics, vol. 89, p. 263 (1986), and JP-A-9-27352 teach a photoelectric conversion device having a solid electrolyte containing a crosslinked polyethylene oxide derivative. However, it turned out as a result of study that the photoelectric conversion devices using these solid electrolytes are insufficient in photoelectric conversion characteristics, particularly in short circuit current density, and their durability are also insufficient.